Sump/Overflow Box advice plz

[ryno368]

well i have a 100g tank and a 20g sump in the back i have a standpipe that is ust a pvc pipe that is cutoff just 1 - 2 inches below the DT water level i have ball valves on both the return and pump pipes. i am getting the flushing sound periodically and i cannot turn on the drain pipe to 100%. i am thinking i need a stronger pump my current one is rated for 560 gph i bought it at lowes. ill post some pics.
when the pump return pipe reaches the top i have it T ed off and have pvc pipes out both sides of the overflow box to create flow in the tank.
well the camera just died and i need to get to sleep but when i wake up i will post pics of inside the overflow box and my plumbing

 

[beaslbob]

IMHO you need to have an actual overflow and not the ball check valves. With an overflow you can run the return full speed and the overflow just drains whatever is pumped back to the tank. All with no adjustements in either the return or overflow pipes.
Some pvc overflows I tested are in this thread:
https://forums.saltwaterfish.com/vb/s...highlight=trap
Plenty of other designs here and around also. But those should at least give you some ideas.
my .02